A group of investigators representing several departments and disciplines at the University of Miami School of Medicine seeks funds to establish a shared confocal laser-scanning microscope facility. This University has many PHS-supported biomedical investigators in need of a high resolution confocal microscope. No confocal microscope facility exists within a 300 mile radius of Miami. In this proposal five groups of major users describe how the optical sectioning and high resolution provided by the requested confocal microscope would benefit their NIH-supported research programs. These programs include studies of permeation pathways through the myelin sheath, specificity of synaptic connections, regulation of acetylcholinesterase expression at the neuromuscular junction, interaction between immune killer cells and their targets, and the effects of spinal cord injury on bone growth and innervation. The descriptions of these projects include images of relevant tissues acquired during confocal microscope demonstrations here, showing the feasibility of the proposed projects and the scientific advantages conferred by confocal microscopy. We document why the requested Bio-Rad system is optimal for these projects. All the major users' projects require the ability of the Bio-Rad system to image simultaneously at least two dyes within the same specimen. We outline an organizational plan to ensure the efficient and skillful operation, long-term maintenance and financial stability of the facility. This plan also ensures that other PHS-supported investigators (nine of whose needs for the confocal microscope are summarized in the Appendix) will have adequate access to the facility. This revised application also addresses the concerns expressed by reviewers of our initial application submitted in 1992.